Computerized transrectal ultrasound of the prostate in a multicenter setup (C-TRUS-MS): detection of cancer after multiple negative systematic random and in primary biopsies.

OBJECTIVE: To improve prostate cancer diagnostic imaging, a computer-based analysis of the transrectal ultrasound signal (C-TRUS) was developed. Until recently, the C-TRUS existed only as a stand-alone device. Now, C-TRUS was developed into a network-compatible module (C-TRUS-MS). This new technology allows users to transmit C-TRUS images from any internet platform to C-TRUS-MS investigation. After analysis, the cancer-suspicious marked images are then retransmitted via internet. Targeted biopsies can then be taken at the urologists' office remotely. MATERIALS AND METHODS: This prospective study investigates whether the rates of prostate cancer detection with C-TRUS-MS "multicenter online" are comparable with those achieved by the stand-alone unit. In addition to patients with a history of multiple systematic random biopsies, a group of patients who had not undergone systematic random biopsies were analyzed. RESULTS: A total of 1,545 digital images (2-23 per patient, median 6) from 57 urologists were transmitted to the analysis center. After analysis, the color-coded images were sent back electronically and utilized for a maximum of six targeted biopsies. C-TRUS-MS was able to detect prostate cancer in 91 patients. In addition, we evaluated 75 patients without any previous random biopsies. In this group, C-TRUS-MS was able to detect prostate cancer in 31 out of 75 patients (41%). CONCLUSION: The results indicate that C-TRUS-MS "online" achieves similar results as the stand-alone system, independent of the user even with little experience in the method. Furthermore, C-TRUS-MS for the first time is able to detect carcinomas in patients without prior biopsies in a high number by taking only six targeted biopsies.

Conditioning stimulus can influence an external urethral sphincter contraction evoked by a magnetic stimulation.

AIMS: To study the effect of a conditioning stimulus on an external urethral sphincter (EUS)contraction evoked by a magnetic stimulation at different time intervals. METHODS: Seven healthy male volunteers underwent EUS pressure measurement. At baseline, magnetic stimulation of the lumbosacral spinal cord above the motor threshold was performed and evoked EUS pressure responses were recorded. The lumbosacral magnetic stimulation was repeated with same intensity, while a selective electrical dorsal penile nerve stimulation below the bulbocavernosus reflex (BCR) threshold was preceding at five different intervals (10, 20, 30, 50, 100 msec). The protocol was performed with empty and full bladder (BLA), and baseline responses were statistically compared to those with combined stimulation. RESULTS: When the dorsal penile nerve electrical stimulation preceded the lumbosacral magnetic stimulation by 20 msec (P=0.0048), 50 msec (P=0.0039), or 100 msec (P=0.0002), the amplitudes of the EUS pressure response with empty BLA were significantly reduced compared to lumbosacral magnetic stimulation alone. With a filled BLA, the amplitudes of the EUS were significantly reduced only at an interval of 50 msec (P<0.0001). CONCLUSIONS: A conditional sensory pudendal stimulation seems to have the capacity to inhibit the external urethral sphincter contraction induced by a magnetic stimulation. The inhibitory effect seems to depend on the latency between the peripheral and lumbosacral stimulation as well as on the degree of BLA filling. It remains to be proved if the neuromodulative effect of the conditional stimulus occurs at a spinal or supraspinal level.